1. Field of the Invention
The present invention relates to a fuel cell stack structure having a stack entity including a plurality of solid electrolyte fuel cells stacked together.
2. Background Information
A conventional fuel cell stack structure includes, for example, a stack entity having a plurality of solid electrolyte fuel cell units and a tie rod that passes through the stack entity to secure and apply pressure to the solid electrolyte fuel cell units. The solid electrolyte fuel cell units are stacked together with a sealing material having a gas sealing capability being disposed between the solid electrolyte fuel cell units.
U.S. Pat. No. 6,344,290 discloses an example of such conventional fuel cell stack structures. With the conventional fuel cell stack structure, it is necessary to tighten the tie rod inside a high-temperature furnace and to absorb the decrease in the thickness of the sealing material in order to maintain the pressure applied by the tie rod. In the conventional fuel cell stack structure disclosed in the above mentioned reference, the tie rod is arranged to be long such that the tie rod tightening task can be accomplished remotely, i.e., the pressure applying force of the tie rod can be controlled remotely.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved fuel cell stack structure and fuel cell stack structure manufacturing method. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.